Common Name: century plant
Type: Herbaceous perennial
Family: Asparagaceae
Zone: 8 to 10
Height: 0.50 to 1.00 feet
Spread: 1.00 to 1.50 feet
Bloom Time: Rarely flowers
Bloom Description: Greenish-yellow
Sun: Full sun
Water: Dry to medium
Maintenance: Low
Flower: Showy
Leaf: Colorful
Attracts: Hummingbirds
Other: Thorns
Tolerate: Drought, Dry Soil, Shallow-Rocky Soil
Culture
Reliably winter hardy to USDA Zones 8-10. Best growth occurs in a sandy/gritty, dry to medium moisture, well-drained soil in full sun. Sharp soil drainage is important, as poorly-drained soils may lead to root rot. Tolerates dry soils and drought.
Noteworthy Characteristics
Agave univittata, known as McKelvey's century plant or thorn-crested agave, is a perennial, rosette-forming succulent native to extreme southern Texas and northern Mexico. It is found at relatively low elevations (less than 300 ft.) in areas around the Gulf Coast and Rio Grande. Rosettes typically reach 1-2' tall and 1.5-3' wide. Dark green, slightly convex leaves (to 15" long) sport a sharp, terminal spine and sharp, curved, marginal spines. Once an individual plant reaches maturity, it will send up an unbranching flowering stalk up to 15' tall. The flowers are around 1.5" in length, with pale green to pale yellow coloration. This agave suckers readily, and can form large colonies over time.
The genus name Agave comes from the Greek word agauos meaning "admirable" or "noble" in probable reference to the very tall flower spikes found on the plants of many species of Agave.
Specific epithet univittata means "one stripe", and refers to the single, light green stripe which can run lengthwise down the center of the leaves on some individuals.
The common name McKelvey's agave refers to Susan Delano McKelvey (1883-1964). A botanist at the Arnold Arboretum, she specialized in lilacs and the flora of the southwestern United States.
'Splendida' forms smaller rosettes compared to the species plant, growing to a maximum of around 12" tall and 18" wide at maturity. The succulent leaves are dark green with a greenish-yellow stripe down the center. The leaves reach 7" long and 2" wide, and are armed with sharp marginal and terminal spines. Mature rosettes will send up a 12' tall flower stalk bearing greenish-yellow flowers that attract hummingbirds.
Problems
No serious insect or disease problems. Slugs and snails may damage foliage. Root rot may occur, particularly in poorly-drained or overly-moist soils.
Uses
Due to the sharp spines and suckering nature of this agave, do not plant near sidewalks, walkway, driveways, or other pedestrian areas. Use in a rock garden, desert garden, or as an accent plant in a container.